Industrial production of toner generally occurs through batch reaction. For example, in an emulsion/aggregation (EA) scheme, two reactors can be used, one to accommodate particle formation and aggregation and then the slurry is transferred to a second reactor to finish the product by coalescence. The residence time of the reaction mixture in either tank can be about the same, and may range up through about 8 hours or more in each reactor.
Uniform and stable additive attachment on the toner can provide suitable and stable tribo and stability to toner properties, such as flowability, over time. Additive attachment as currently practiced can be a mere blending or mixing which can result in batch to batch variation. Additives can detach over time, as well as embed into the toner particles, which can cause reduction in tribo and stability changes.
A continuous process, in conjunction with a method to improve the attachment of surface additives to toners, can provide advantages over batch aggregation and coalescence (A/C) by providing one or more of faster and/or efficient mixing, higher yield, fewer impurities, flexible A/C conditions, time and cost savings, and increased surface area to volume ratio that results in good mass and heat transfer, as well as maintain tribo values and stability of the resulting toner particles.